Apparatus and method for targeting and/or installing fastners into an intramedullary nails

ABSTRACT

A method and apparatus for installing a number of distal screws into an intramedullary nail implanted in a patient. The apparatus includes a foundation which is fixedly coupled to the patient, a targeting insert having a targeting spike, a guiding insert for guiding an installation tool used in installing a distal screw, a targeting/guiding device coupled to the foundation and adaptable for having the targeting insert and the guiding insert coupled thereto, and a handle removably coupled to the targeting/guiding device. When the targeting insert is coupled to the targeting/guiding device, the targeting/guiding device may be movable by an operator or surgeon with the use of the handle so as to align the targeting spike with a respective distal screw hole in the intramedullary nail. Afterwards, the targeting/guiding device may be locked in place by the operator or surgeon with the use of the handle, the targeting insert removed, and the guiding insert coupled to the targeting/guiding device. Such guiding insert enables the installation tool to be properly guided when installing a distal screw into the respective distal screw hole.

This application is a continuation of Ser. No. 09/190,033, filed Nov.11, 1998, now U.S. Pat. No. 6,129,729.

BACKGROUND OF THE INVENTION

The present invention relates to positioner devices and, morespecifically, to such devices for determining and maintaining or holdinga specific position or target such as may be needed in orthopaedicsurgery for the placement of locking

Bone fractures, such as long bone fractures of the upper and lowerextremities, may be stabilized with metal rods or so-calledintramedullary nails that are implanted into the hollow center orso-called intramedullary canal of these bones. However, an implantedintramedullary nail may provide only limited stability to a fracturedbone. That is, the two ends of the fractured bone may rotate, angulateand/or telescope on the implanted nail.

The intramedullary nails may achieve greater stability by the use oflocking screws that may pass through the bone and the intramedullarynail. Such locking screws may be placed at opposite ends of theimplanted intramedullary nail and may lock the parts or sides of thefractured bone to the implanted intramedullary nail. As a result, thelocking screws may prevent the fractured bone from rotating, angulatingand/or distracting upon the implanted intramedullary nail.

The region of the bone where the nail is implanted is identified asproximal and the opposite end of the intramedullary nail is distal.Intramedullary nails have two proximal and two distal screw holes. Thelocking screws should be placed precisely through both the bone andscrew holes in the implanted intramedullary nail. Placement of theproximal transverse locking screws, near to the insertion point of theintramedullary nails may be relatively simple. However, placement of thetwo transverse locking screws across both the bone and distal end of theintramedullary nail may be relatively difficult.

A number of steps may be undertaken to successfully place locking screwsacross both a fractured bone and an implanted intramedullary nail.First, X-rays or the like may be used to locate the screw holes in theintramedullary nail. Second, screw holes may be drilled through the boneon either side of each screw hole. Third, the length of the lockingscrew needed to pass through both the bone and the intramedullary nailmay be determined by passing a depth gauge or the like through thedrilled holes and intramedullary nail. Fourth, the selected lockingscrew or screws are implanted, transfixing the bone and theintramedullary nail.

The above-described steps for placement of the proximal locking screwsmay be readily accomplished with a proximal based outrigger bushing thatis attached to the proximal end of the implanted nail. Such outriggerbushing may provide rigid concentric alignment with the proximal screwholes so as to enable rapid and reliable drilling, measurement, andplacement of the proximal screws. On the other hand, an outriggerbushing with a proximal origin for the distal screw holes may notperform satisfactorily due to the mechanical stress on the outriggerand/or the unpredictable distortion of the distal end of theintramedullary nail during implantation.

Distortion of the distal end of an intramedullary nail may occur as itis implanted into a bone. That is, the distal end of the nail mayrotate, angulate and/or deflect within the intramedullary canal of thebone. Accordingly, a fixed proximal based outrigger bushing may notcompensate for the actual position of the distal screw holes and may notfunction adequately.

An adjustable-type outrigger bushing may compensate for the distortionof the distal end of an implanted intramedullary nail. However, suchadjustable-type outrigger bushing may require excessive tinkering toobtain correct alignment with the screw holes in the implanted nail.This tinkering may necessitate an increased use of X-rays and as suchmay increase undesirable X-ray exposure to the surgeon, patient andoperating room staff, and may also lengthen the surgical procedure.

Outrigger bushings with a proximal origin for the distal screws mayeffectively have a long lever arm. Uncontrollable micromotion of suchlong lever arm may prevent the successful use of these devices. Evenwhen an outrigger bushing, such as the adjustable-type outrigger bushingis eventually aligned with the distal screw holes, the alignment may notbe sustained due to micromotion.

The combined mechanical difficulties of the proximal based outrigger andthe distortion of the implanted nail have thwarted the successfuldevelopment of a proximal based outrigger bushings for the distal screwholes.

To place distal locking screws in an implanted interlocking nail thelocation of the distal screw holes should be known. However, the distalend of the nail may be hidden from view within the intramedullary canalof the bone and visualization of the distal screw holes may requireX-ray guidance provided by a portable adjustable X-ray machine or thelike in the operating room. Such X-ray machine may be manipulated to aposition in which the path of the x-ray beam is parallel with the longaxis between a single set of screw holes in the intramedullary nail.When this alignment is accomplished, the X-ray appearance of the screwholes may be substantially perfect circles. The X-ray machine may bemaintained in axial alignment with a distal screw hole throughout thepreviously-described second through fourth steps for placement of adistal interlocking screw.

The lack of success of proximal origin outrigger bushings for the distallocking screws has stimulated the development of a number of devices andtechniques to accomplish the placement of these screws. However,although these devices may locate the distal screw holes and facilitatethe drilling of holes in bone, these devices may not provide guidancewhich may be needed for the steps of measuring the length of the lockingscrew and/or placing the locking screw across the bone andintramedullary nail. The steps of measuring the optimum length of thelocking screw and placing the selected screw may be very difficult toachieve. The successful drilling of a screw hole across the bone andintramedullary nail may not facilitate the necessary and technicallydifficult steps of measuring or implanting the locking screw.

There is a substantial amount of empty space concentrically surroundingthe implanted intramedullary nail. The drilled screw hole in the bonemay not be of sufficient length or thickness to serve as a bushing toalign the depth gauge or locking screw with the screw hole in theinterlocking nail. The depth gauge and locking screw will frequentlymiss the screw hole and deflect off the intramedullary nail. Therefore,measuring the length of the locking screw and the implantation of themeasured locking screw may necessitate the use of additional X-rays and,as such, may result in excessive x-ray exposure to the surgeons, patientand/or operative team and may substantially lengthen the surgicalprocedure regardless of whether the drilling of the screw hole(s) acrossthe bone and intramedullary nail was successful.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the present invention is to provide an apparatus and methodfor targeting and/or installing screws into an intramedullary nail whichenables distal locking screws to be accurately, rapidly and reliablyplaced in the intramedullary nail.

Another object of the present invention is to provide an apparatus asaforesaid which is relatively simple to assemble and use. Such assemblyand/or use may utilize skills which a surgeon already possesses or isfamiliar with and may utilize equipment already present in an operatingroom.

The present apparatus and method may simplify the steps of drilling,measuring and placing of the distal locking screws, therebysubstantially shortening the amount of time required to properly insertthe distal locking screws. Further, the present apparatus may enablesuch proper insertion of the distal locking screws with a reduced orlesser use of X-rays as compared to other techniques. Thus, the presentapparatus and method may shorten operating room time and minimize x-rayexposure to the surgeon, operating staff and/or patient.

In a preferred embodiment, the present apparatus has five majorcomponents. Such components may be fabricated predominantly from asignificantly radiolucent plastic material. The five major componentscan rapidly be assembled by the surgeon. These components include afoundation which is attached to the patient, a locking-targeting-guidesupported by the foundation, a handle attached to thelocking-targeting-guide which may be used to position thelocking-targeting-guide over the distal screw holes of the implantedintramedullary nail, and a set of two interchangeable inserts which areinserted into the locking-targeting-guide. The first of such inserts maybe used to “target” or align a portion of the locking-targeting-guidewith the distal screw hole and the second of such insert may be used toguide a drill, drill bit, depth gauge, screwdriver and other suchdevices which may be utilized in the installation of the distal screw.

Other objects, features and advantages according to the is presentinvention will become apparent from the following detailed descriptionof the illustrated embodiments when read in conjunction with theaccompanying drawings in which corresponding components are identifiedby the same reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of three basic components of an apparatus fortargeting and/or installing screws into an intramedullary nail accordingto an embodiment of the present invention;

FIG. 2 is a diagram of an alignment rod restraining plate;

FIG. 3 is a diagram of a restraining plate locking and release mechanismof an alignment rod restraining plate of FIG. 1;

FIG. 4 is a diagram of the apparatus of FIG. 1;

FIG. 5 is a diagram of the apparatus of FIG. 4 with a targeting insert;

FIG. 6a is an isometric view of a neoprene fixation strap;

FIG. 6b is an isometric view of the present apparatus of FIG. 1 attachedto a broken femoral bone by metal fixation pins;

FIG. 7 is a diagram of the targeting insert of FIG. 1;

FIG. 8 is a diagram of the cannulated insert of FIG. 8;

FIG. 9 is a section diagram of the cannulated insert of FIG. 8;

FIG. 10 is a diagram of a locking-targeting-guide and the alignment rodrestraining plate of FIG. 2;

FIG. 11 is an exploded diagram of the locking-targeting-guide of FIG.10;

FIG. 12 is a diagram of a middle plate assembly of thelocking-targeting-guide of FIG. 10;

FIG. 13 is an exploded diagram of the middle plate of FIG. 12;

FIG. 14 is a diagram of the bottom of the middle plate of FIG. 12;

FIG. 15 is a diagram of the base portion of the locking-targeting-guideof FIG. 10;

FIG. 16 is an exploded diagram of the base portion of thelocking-targeting-guide of FIG. 15;

FIG. 17: is a partial exploded diagram of a sliding lock plate withinthe base portion of the locking-targeting-guide of FIG. 15;

FIG. 18 is a partial diagram of the base portion of thelocking-targeting-guide of FIG. 10;

FIG. 19 is a diagram of a brake-bearing;

FIG. 20 is a partial isometric exploded diagram of the brake-bearing ofFIG. 19;

FIG. 21 is an isometric exploded view of the brake-bearing of FIG. 19;

FIG. 22, is a diagram of the brake-bearing of FIG. 19 arranged on avertical alignment rod in which the brake-bearing has not beencompressed and is not gripping the vertical alignment rod;

FIG. 23a is a diagram of a non-compressed brake-bearing positionedbetween upper and lower universal joints wherein the brake-bearing hasnot been compressed and is not gripping the vertical alignment rod;

FIG. 23b is a diagram of an activated brake-bearing compressed betweenthe upper and lower universal joints wherein the compressedbrake-bearing is gripping the vertical alignment rod;

FIG. 23c is a diagram of the activated brake-bearing which has followedand gripped the angled vertical alignment rod;

FIG. 24 is a partial isometric exploded diagram of thelocking-targeting-guide of FIG. 10;

FIG. 25 is another partial isometric exploded diagram of thelocking-targeting-guide of FIG. 10 which shows upper vertical alignmentrod segments passing through upper universal joints and brake bearings;

FIG. 26 is another partial isometric exploded diagram of thelocking-targeting-guide of FIG. 10 which shows upper vertical alignmentrod segments passing through upper universal joints, brake bearings, andlower universal joints;

FIG. 27 is a diagram of the locking-targeting-guide of FIG. 10 and avertical alignment rod restraining plate which shows upper verticalalignment rod segments passing through upper universal joints, brakebearings, lower universal joints and a base component;

FIG. 28 is an isometric diagram of a foundation of the apparatus of FIG.1;

FIG. 29 is an exploded isometric diagram of the foundation of FIG. 28;

FIG. 30 is a partial exploded isometric diagram of the foundation ofFIG. 28 which shows a lock release mechanism;

FIG. 31 is a diagram of the lock release mechanism of the foundation ofFIG. 30 wherein lower vertical alignment rods are erect;

FIG. 32 is a diagram of the lock release mechanism of the foundation ofFIG. 30 wherein the lock has been lowered and the vertical alignmentrods are able to move;

FIG. 33 is an isometric diagram of upper and lower vertical alignmentrod segments;

FIG. 34 is an isometric diagram of a handle of the apparatus of FIG. 1;

FIG. 35 is an isometric diagram of the handle of FIG. 34;

FIG. 36 is an isometric diagram of a lock release reset mechanism of thehandle of FIG. 35;

FIG. 37 is an isometric exploded diagram of the handle of FIG. 34;

FIG. 38a is a diagram of the handle of FIG. 34 illustrating a positionof a handle-trigger when it is inserted into thelocking-targeting-guide;

FIG. 38b is a diagram of the handle of FIG. 34 illustrating the positionof the handle-trigger when it has been compressed and locked into thelocking-targeting-guide;

FIG. 38c is a diagram of the handle of FIG. 34 illustrating the positionof the handle-trigger when it has been completely compressed deploying aprobe into the locking-targeting-guide and releasing the lock mechanism;

FIG. 39a is a diagram of the lock release reset mechanism of the handlein which the latch and lock/release controller are not engaged;

FIG. 39b is a diagram of the lock release reset mechanism of the handlein which the latch and lock/release controller are engaged;

FIG. 39c is a diagram of the lock release reset mechanism of the handlein which the latch and lock/release controller have disengaged and thelatch is behind the lock/release controller;

FIG. 40 is a diagram of a handle and locking-targeting-guide accordingto another embodiment of the present invention;

FIG. 41 is a diagram to which reference will be made in explaining theoperation of the handle and locking-targeting-guide of FIG. 40;

FIG. 42 is a diagram of the locking-targeting-guide of FIG. 40;

FIG. 43 is an exploded diagram of the locking-targeting-guide of FIG.42;

FIGS. 44a and 44 b are diagrams of the handle of FIG. 40;

FIG. 45a is a cross-sectional diagram of the locking-targeting-guide ofFIG. 40 when it is not engaged to the handle of FIG. 40;

FIG. 45b is a partially exploded cross-section of thelocking-targeting-guide of FIG. 40;

FIG. 46a is a diagram of the locking-targeting-guide of FIG. 40 in whichthe handle is not engaged;

FIG. 46b is a diagram of the engaged locking-targeting-guide and handleof FIG. 41 in which the handle latch and lock/release controller areengaged;

FIG. 46c is a diagram of the engaged locking-targeting-guide and handleof FIG. 41 in which the handle is fully compressed;

FIG. 46d is a diagram of the locking-targeting-guide of FIG. 41 in whichcompression of the handle has activated a locking mechanism of thelocking-targeting-guide;

FIG. 47 is a diagram of a foundation according to another embodiment ofthe present invention; and

FIG. 48 is a diagram of a foundation according to another embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An apparatus for targeting and/or installing screws into anintramedullary nail according to an embodiment of the present inventionis illustrated in FIGS. 1 and 4. As shown therein, such apparatus 1generally includes a foundation 10, a locking-targeting-guide 12, and ahandle 14. The foundation 10 may be attached to a patient and maysupport the locking-targeting-guide 12. The locking-targeting-guide 12may be moved to a desired position or alignment when supported by thefoundation and may lock onto the foundation by use of a lockingmechanism when the desired alignment is obtained. The handle 14, whichmay be detachably coupled to the locking-targeting-guide 12, serves toposition the locking-targeting-guide and trigger the locking mechanismwithin the locking-targeting-guide 12 when the desired alignment isachieved.

With reference to FIGS. 6A and 6B, apparatus 1 is used after anintramedullary nail 260 has been implanted into a fractured femur 262,stabilizing the fracture 264. X-rays emitted from an X-ray machine havebeen aligned with a respective distal screw hole or holes 268 a or 268b. The position of the screw hole(s) are noted and a line is drawn onthe skin over the screw hole(s). Such line provides a relative guidemark for positioning the foundation 10 on the patient.

The implanted intramedullary nail 260 is visualized on an X-ray monitor254 as a radio-opaque black bar 256. The two screw holes 268 a and 268 bare seen on the X-ray monitor 254 as two circles 270 a and 270 b. Whenan alignment spike 38 (which may be fabricated from a metal material) ofa targeting insert 24 is aligned over the hole 268 a, the spike 38 isseen as a radio-opaque black circle centered within the X-ray image 270a of screw hole 268 a.

The foundation 10 has a relatively large central fenestration 154 whichis centered over the lines or marks drawn on the patient. A foundationframe 168 of foundation 10 can be fixed on the skin over the distalscrew holes of the implanted intramedullary nail by strapping it inplace with a wide elastic neoprene band 250. The outer surface of theneoprene band 250 may have a Velco knapped surface 252 and may haveVelcro hook attachments 248 at the terminal ends of the outer surface.The inner surface 246 of the neoprene band may be smooth. The foundation10 may be strapped in place with other types of elastic devices or thelike. Alternatively, the foundation can be held in place by use of anumber of metal fixation pins 25 that are each placed or drilled througha fenestration 164 (FIG. 28) of a clamp 160 in the foundation 10 intothe underlying bone. In this later situation, after the fixation pin orpins 25 have been drilled into the bone, the clamp or clamps 160 aretightened so as to rigidly hold the fixation pin or pins 25. As aresult, the foundation 10 is held to the underlying bone.

In a relatively thin individual or patient; the elastic neoprene strap250 alone may provide a stable attachment of the foundation 10 to thelimb. In a larger patient or one with more fat, a number of fixationpins 25 may be needed to provide a stable attachment between thefoundation 10 and the underlying bone. Alternatively, the elasticneoprene strap and fixation pins 25 can also be used together foroptimum attachment between the foundation 10 and the limb and underlyingbone.

With reference to FIGS. 28-32, the foundation 10 has a plurality ofvertical alignment rods 146 that are releasably rigidly held normal to asurface of a frame 170 of the foundation 10. The plurality of alignmentrods 146 are basically positioned at the corners of the frame 170 andare arranged such that the ends of the vertical alignment rods areseated in spherical bases 150 which, in turn, are arranged or restrainedin sockets 174 of a socket frame 172 by restraining collars 152 so as tocreate respective ball joints.

Each of the spherical bases 150 has a flat bottom surface 175 which isin contact with a flexible restraining plate 180 within the foundation10. Each of the vertical alignment rods 146 may be held in a verticalposition by pressure of the restraining plate 180 against the flatbottom 175 of the respective spherical base 150.

A freedom lever 158 in the foundation can lower the restraining plates180 away from the spherical bases 150. The same freedom lever 158 canalso be used to raise the flexible restraining plates 180 against thespherical bases 150.

Simple manipulation of the alignment rods can bring the flat surfaces ofthe spherical bases 175 into proper contact with the raised restrainingplates 180. Such manipulation or maneuver may realign, if necessary, thevertical alignment rod or rods 146 into a rigid vertical position. Whenthe restraining plates 180 are lowered away from the spherical bases150, the vertical alignment rods 146 can freely rotate through arelatively large spherical like arc.

On opposite sides of the frame 170 of the foundation 10 are bars 166over which the neoprene strap 250 can be passed to fix the foundation tothe injured limb.

The foundation 10 has a plurality of pivotable clamps 160 to acceptfixation pins 25. Each of the fixation pins 25 may be held in arespective clamp 160 by tightening a screw 162. The clamps 160 can pivotto enable proper positioning of the fixation pins 25 into the underlyingbone. In addition to holding the fixation pin, tightening the screw 162will also prevent rotation of the clamp 160.

The freedom lever 158 is pivotally coupled to the foundation 10 at 186 aand a conjoined lock/release ring 176. Moving the freedom lever 158lifts and lowers the conjoined lock/release ring 176 which brings therestraining plates 180 in contact with or moves them away from thespherical bases 150 of the vertical alignment rods 146.

The conjoined lock/release ring 176 is pivotally coupled to thefoundation lo by a plurality of pivot bars 184. Such pivot bars 184 areattached to the foundation at 186 a, 186 b, 186 c, 186 d and attached tothe conjoined lock/release ring 176 at pivot recesses 188.

The freedom lever 158 is arranged so as to move within an oblique slot156 on the surface of the foundation. The long axis of the slot 156 maynot be parallel to the plane of rotation of the freedom lever 158.Rotation of the freedom lever 158 in slot 156 may cause the freedomlever to experience a spring deformation slightly toward the center ofthe foundation 10. At an end of the slot 156 is a recess 157 that is inparallel alignment with the rotation plane of the freedom lever 158.When the freedom lever 158 reaches the recess 157 the spring deformationproduced by the oblique orientation of the slot 156 is released. Uponsuch movement, the freedom lever 158 will snap into the recess 157.

When the freedom lever 158 is placed in a vertical position in the slot156, which lifts the conjoined lock/release ring 176, it may contact atension post 182 slightly before it is fully vertical. The freedom lever158 may experience a slight spring deformation against the tension post182 when it is completely vertical. Such spring deformation may hold thefreedom lever 158 in the recess 157.

With reference to FIG. 33, each vertical alignment rod 146 may havecoupled thereto a corresponding upper alignment rod segment 138, whichmay be shorter in length than the vertical alignment rod. Unlike thealignment rod 146 which rises from spherical base 150 held in thefoundation 10, the upper vertical alignment rod segment 138 is containedwithin the locking-targeting-guide 12.

At an upper end of the lower alignment rod segment 146 there is areceptacle 148 to receive the tines of a snap/lock 142 extending fromthe bottom of the upper alignment rod segment 138. The snap/lock tines142 may be compressed together when passed through a cylindrical recess190 and may re-expand in a recess 192, whereupon the snap/lock tines maybe locked in place.

With reference to FIGS. 1, 28, and 29, the lower vertical alignment rodsegments 146 should be held in a vertically normal position tofacilitate the attachment of the upper alignment rod segments 138thereto. That is, if each lower alignment rod segment 146 were free toindependently move such attachment of rod segment 138 would beexceedingly difficult. Spherical base restraining plates 180 help toensure that the vertical alignment rods are kept vertical.

With reference to FIGS. 24 and 25, the upper alignment rod segments 138are restrained in the locking-targeting-guide 12. Each upper alignmentrod segment 138 has a wide flattened cap 144 on one end thereof thatrests on the top surface of the locking-targeting-guide 12 and preventsthe upper alignment rod segment 138 from falling therethrough. Theopposite end of each upper segment has a reduced diameter shaft 140 andsnap/lock tines 142. The reduced diameter shaft 140 and the snap/locktines enter into the receptacles 148 in the top of the lower alignmentrod segments 146 (FIG. 33). The snap/lock tines 142 from the upperalignment rod segments 138 protrude from the lower surface of thelocking-targeting-guide 12.

With reference to FIGS. 2, 3 and 27, an alignment rod restraining plate16 is snapped onto the top surface of the locking-targeting-guide 12.The restraining plate 16 holds the upper alignment rod segments 138within the locking-targeting-guide 12, until the upper alignment rodsegments 138 are joined to the lower alignment rod segments 146 and thelocking-targeting-guide 12 is ready to be positioned. The alignment rodrestraining plate 16 may also prevent motion of thelocking-targeting-guide 12 on the assembled alignment rods until thelocking-targeting-guide 12 is to be used.

With reference to FIGS. 1, 2, 3, 10, and 27, the alignment rodrestraining plate 16 is clipped onto the top of thelocking-targeting-guide 12. That is, the alignment rod restraining plate16 snaps into the large central fenestration 45 on the top surface oflocking-alignment-guide. Finger grips 18 extend from a flexible springplate 23 which rises from an inverted hemispherical shell 22 thatdescends from the lower surface of the alignment rod restraining plate16. When the hemispherical shell 22 is placed into the centralfenestration 45 of the locking-targeting-guide 12 locking edges 21engage insert locking groove 52. When the finger grips 18 are compressedtogether against the force of the spring plate 23, the locking edges 21disengage from the insert locking groove 52, and the alignment rodrestraining plate 16 can be lifted from the top of thelocking-targeting-guide 12. The alignment rod restraining plate 16 has aplurality of cylindrical bosses 20 on the top surface that correspond torecesses 19 on the bottom surface. The flattened tops 144 of the uppervertical alignment rod segments 138 fit into the plurality of matchingrecesses 19.

With reference to FIGS. 5, 6, 7, 8, 9 and 10, after the alignment rodrestraining plate 16 has been removed from the locking-targeting guide,targeting insert 24 is placed into the central fenestration 45. Thetargeting insert 24 may have a locking mechanism for holding it into thecentral fenestration 45 similar to that previously described for thealignment rod restraining plate 16. Such locking mechanism may includeinsert finger grips 28 which extend from a flexible spring plate 32which rises from inverted hemispherical shell 30 that descends from thelower surface of the support plate 26. The targeting insert 24 has metalalignment spike 38 that protrudes from a solid central support cylinder36. When the metal alignment spike 38 is pointing directly at a screwhole and the long axis of the spike is aligned parallel with the x-raybeam it will appear as a circular spot on an x-ray-monitor.

When the locking-targeting-guide 12 has been positioned, the targetinginsert 24 is removed from the central fenestration 45 and replaced withcannulated insert 34. The cannulated insert has a centrally locatedcylinder 40 that has a cannulated center 41. A drill, a depth gauge, ascrew driver, and so forth may be guided to the respective screw hole byuse of the cannulated insert 34. As is to be appreciated, a plurality ofcannulated inserts may be used each having respective dimensions and/orfeatures so as to accommodate different size drills, depth gauges, screwdrivers and the like. Alternatively, a single cannulated insert 34 maybe used with a drill, depth gauge, and screw driver that have identicaldiameters.

The locking-targeting-guide 12 will now be further described withreference to FIGS. 10-18.

The locking-targeting-guide 12 may be considered as having four majorcomponents. Such components include an outer frame 46, a base component58, a movable middle plate 66 and a plurality of brake-bearings 64. Eachof the four components will now be described.

The outer frame 46 is ideally formed from a radiolucent plastic typematerial and has a top surface and side surfaces. Two opposing sideseach have a relatively large slot 56 through which reset handles 54 ofthe middle plate 66 project and move. Another side has a docking bayslot 59 where the outer frame 46 engages a docking bay 60 of the basecomponent 58. Such docking bay is where the positioning handle 14attaches to the locking-targeting-guide 12. On the top surface of theouter frame 46 a plurality of centrally cannulated universal joints 42 aare mounted.

Each of the upper universal joints 42 a have an outer ring 42 b and aninner ring 42 c. The lower surface of the inner ring 42 c ishemispherical in shape and contacts a respective brake-bearing 64. Theupper vertical alignment rod segment 138 passes through the centralcannulation of the inner ring 42 c of the upper universal joint 42 a. Inthis embodiment, the number of assembled vertical alignment rods,brake-bearings 64, and universal joints are equal.

The top of the outer frame 46 has the large central fenestration 45which receives the vertical alignment rod restraining plate 16, thetargeting insert 24 and the cannulated insert 34. The centralfenestration 45 may not extend through the complete thickness of the topsurface of the outer frame 46 and may have a shallow cylindrical shape.On the wall of the cylinder is locking groove 52 into which locking edge21 (FIG. 3) of the alignment rod restraining plate 16 and locking edge29 (FIG. 9) of the inserts lock. The cylinder 45 terminates in insertblock plate 50 having a relatively small central fenestration 48.

The outer frame 46 of the locking-targeting-guide 12 is joined to thebase component 58 by a plurality of assembly screws 44. Alternatively,the frame 46 may be coupled to the base component 58 by other types offasteners or by other means of attachment. The plurality of screws 44are arranged in recesses 62 so as to be recessed into the top surface ofthe locking-targeting-guide 12. These screws engage matching threadedrecesses 100 located in the top of spring support pillars 70 of the basecomponent 58. The open end of the bottom of the outer frame 46 of thelocking-targeting-guide 12 may be coupled to a skirt 111circumferentially extending around the base component 58.

A further description of the base component 58 of thelocking-targeting-guide will now be provided with reference to. FIGS.15-18. The base component has a top plate 112 and a base plate 110 thatare joined together. A slidable lock plate 105 is arranged between thetop plate 112 and the base plate 110.

The top plate 112 has a plurality of spring support pillars 70 eachsurrounded by a locking spring 68 (FIG. 11). The spring support pillars70 extend internally through the locking-targeting-guide so as tocontact (or be adjacent to) the inner bottom surface of the outer frame46 to receive the assembly screws 44.

The top plate 112 and the base plate 110 have a plurality of matchingfenestrations or holes. That is, such plates have fenestrations 102 and114 through which the vertical alignment rods may pass; centralfenestrations 104 and 98 through which the alignment spike 38 of thetargeting insert 24, the depth gauge, screwdriver and locking screw maypass; and a plurality of matching rectangular catch fenestrations 106and 108 into which catches 94 (FIG. 14) from the bottom of middle plate66 enter.

As previously mentioned, the sliding lock plate 105 is arranged in aspace between the top plate 112 and the base plate 110. The sliding lockplate 105 may have two degrees of limited horizontal freedom. An elasticor rubber band 122 or the like may be arranged in a band groove 120 onthe sliding lock plate 105 and may push the sliding lock plate 105against restraining ridges 109 such that contact surfaces 107 of thelock plate 105 engage the restraining ridges 109. The elastic band 122is supported on the inner surface of the base plate 110 by two elasticband posts 115.

Extending from two sides of the sliding lock plate 105 are a pluralityof horizontal locking bars 116. The horizontal locking bars 116 arepositioned between the matching rectangular catch fenestration 106 and108. When the plurality of catches 94 descend through the fenestrations106 they will engage the horizontal locking bars 116.

The top plate 112 has the docking bay 60 into which a handle dockingrostrum 196 (FIG. 34) is inserted. The docking bay 60 has a rostrumrecess 61 into which a rostrum key 194 (FIG. 34) is inserted. Therostrum recess 61 and rostrum key 194 provide increased contact surfacearea between the docking bay 60 and the handle docking rostrum 196. Suchincreased surface area may improve the stability and control of thehandle 14 in the locking-targeting-guide 12.

The docking bay 60 fits into docking bay recess 113 of the base plate110. An open or trigger slot 19 is arranged on the back surface of thedocking bay 60. Trigger edge 118 of the sliding lock plate 105 entersthe docking port 60 through the trigger slot 119. Pressure against thetrigger edge 118 will displace the sliding locking plate 105 against theforce of the elastic band 122. Such displacement of the sliding lockingplate 105 may release the plurality of catches 94 held by the horizontallocking bars 116. This release would then permit the middle plate 66 tobe propelled upwards by the locking springs 68.

The middle plate 66 will now be further described with reference toFIGS. 11-14. The middle plate 66 is located within the locking-targetingguide 12. Spring support pillars 70 pass through fenestrations 84 in themiddle plate 66, and two of such pillars also pass through fenestrations86 of the armature restraining plate 71. The middle plate 66 may besupported by the locking springs 68 and may have two degrees of verticalfreedom with regard to the spring support pillars 70.

The top of the middle plate 66 has a shallow tray 75 in which anarmature 74 is arranged that holds a plurality of universal joints 76 a.Each universal joint 76 a has an outer cylinder 76 b and an innercylinder 76 c which are arranged such that the axes of rotation of theouter cylinder 76 b and inner cylinder 76 a is normal to each other. Thenumber of universal joints 76 a may be equal to the number of verticalalignment rods. A plurality of catches 94 extend from the bottom surfaceof the middle tray. Depression of the middle plate 66, by pressureapplied to the reset plates 54, will compress the supporting lockingsprings 68 and permit the catches 94 to engage the horizontal lockingbars 116 (FIG. 16) of the sliding locking plate 105.

The armature 74 may have 2 degrees of freedom within the constraints ofthe middle plate tray 75. The armature 74 is substantially preventedfrom vertical motion by restraining plate 71 which is attached to themiddle plate tray 75. In the current embodiment, the restraining plate71 and tray 75 are attached by a plurality of screws 72 that passthrough fenestrations 90 of the armature restraining plate 71 and areplaced into screw pillars 92. However, the present invention is not solimited and other means may be used for coupling together therestraining plate 71 and tray 75.

A universal joint 76 a is mounted at the end of each arm of the armature74. Inner ring 76 c of each universal joint 76 a has a hemisphericaldepression on its upper surface which may contact a respectivebrake-bearing 64. Beneath each universal joint is a relatively largealignment rod fenestration 80 in the middle plate 66.

There are concentric central fenestrations in armature restraining plate88, armature 78, and middle plate 82 through which the alignment spike38 of the targeting insert 24, the depth gauge, the screwdriver andlocking screw will pass. The central fenestration 78 of the armature islarger than the central fenestrations of either the restraining plate 71or the middle plate 66 to prevent impingement on insert 24, depth gaugeor screw driver with motion of the armature 74.

Reset plates 54 are arranged on opposite sides of the middle plate andextend outwardly therefrom. The reset plates 54 enable thelocking-targeting-guide 12 to be released and reset. That is, downwardpressure applied to the reset plates 54 will depress the middle plate 66and compress the locking springs 68. Such downward pressure is continueduntil an audible/palpable click occurs which indicates that the catches94 on the bottom of the middle plate 66 have engaged the horizontallocking bars 116.

Upon depressing middle plate 66 onto base component 58, engagement edges95 of catches 94 may contact horizontal locking bars 116 (FIG. 16).Further depression of the middle plate 66 may produce pressure fromslide surfaces 97 against the horizontal locking bars 116. The downwardpressure on middle plate 66 is continued until the slide surfaces 97have passed completely below the locking bars 116, whereupon the lockingbars snap back to their pre-displacement position and engage lockingledges 96 of catches 94.

A locking mechanism within the locking-targeting-guide 12 will now bedescribed with reference to FIG. 19-i. Such locking mechanism mayreversibly rigidly grip a vertical alignment rod. The locking mechanismis composed of a cannulated spherical deformable braking-bearing 64positioned between an upper cannulated universal joint 42 a and a lowercannulated universal joint 76 a. The upper universal joint 42 a isincorporated into the top of the outer frame 46 of thelocking-targeting-guide 12 and the lower universal joint 76 a is set atthe end or extremity of armature 74. A respective vertical alignment rodpasses through central cannulation 130 of the brake-bearing 64 and theupper and central fenestrations in the inner rings of the upper andlower universal joints. There is a set of upper and lower universaljoints with an interposed brake bearing to grip each vertical alignmentrod.

The locking mechanism is activated by compression of the upper and loweruniversal joints 42 a, 76 a against the brake-bearing 64. When axialpressure is applied against the brake-bearing 64 by the upper and loweruniversal joints 42 a, 76 a the brake-bearing 64 will deform and gripthe assembled vertical alignment rod. This will lock thelocking-targeting-guide 12 in the selected position. The locked positionis sustained for as long as the universal joints 42 a, 76 a compress thebrake-bearing 64.

Deformation of the brake-bearing 64 may occur with axial compression.Such axial compression may be provided by placing the brake-bearing 64between two universal joints 42 a, 76 a, in which the lower universaljoint 76 a mounted on the armature 74 has 4 degrees of horizontalfreedom to follow the motion of the assembled vertical alignment rod.The upper and lower universal joints 42 a, 76 a can produce axialcompression on the break-bearing 64 regardless of the position of theassembled vertical alignment rod.

Sustained compression of the upper and lower sets of universal joints 42a, 76 a against the brake-bearing 64 is provided by the locking springs68 that support the middle plate 66. However, when the catches 94 of themiddle plate 66 have engaged the horizontal locking bars 116, the middleplate is held distracted or removed from the outer frame 46. In suchsituation, the upper and lower universal joints 42 a, 76 a are heldapart, whereupon the brake-bearings 64 may rest upon the upperhemispherical surfaces of the inner ring 76 c of the lower universaljoint 76 a.

Release of the catches 94 will permit the compressed locking springs 68to forcibly expand. The springs will forcibly lift the middle plate 66(with lower universal joints 76 a) and brake-bearings 64 against theupper universal joints 42 a. The sustained force of the released springs68 will produce axial compression on the upper and lower universaljoints 42 a, 76 a against the brake-bearings 64. The compression of thebrake-bearings 64 will cause the brake-bearings to deform and grip thecentrally located assembled vertical alignment rods. Such grip of thebrake-bearings 64 against the assembled vertical alignment rods willlock the locking-targeting-guide 12 in the desired position. Thebrake-bearings 64 will remain locked against the assembled verticalalignment rods until the locking springs 68 are compressed such as whichmay occur when the middle plate 66 is lowered.

Lowering of the middle plate 66 and compression of the locking springs68 is accomplished by applying downward pressure on the reset plates 54.Such pressure on the reset plates 54 will terminate the axialcompression of the universal joints 42 a, 76 a against the brake-bearing64.

When the axial compression is terminated the deformation of thebrake-bearing 64 may be reversed so as to return to its original shape.When the brake-bearing 64 returns to its original or resting shape, itmay not grip the centrally located assembled vertical alignment rod. Torelease or terminate the axial compression, the reset plates 54 aredepressed until an audible/palpable click occurs indicating that thecatches 94 have engaged the horizontal locking bars 116. As a result,the locking-targeting-guide is reset and again has a number (such assix) of degrees of freedom with regard to the assembled verticalalignment rods.

The brake-bearing 64 will now be further described with reference toFIGS. 19-23. As previously indicated, the present embodiment utilizes abrake-bearing 64 for each assembled vertical alignment rod. Aspreviously described, when axial compression is applied to thebrake-bearing 64, it will reversibly deform from a spherical shape andgrip an assembled vertical alignment rod that passes through the brakebearing center. The brake-bearing 64 will return to a resting sphericalshape when such compression is terminated.

The brake-bearing 64 is divided into upper and lower hemispheres, which,in turn, are divided into a plurality of substantially identicalspherical segments 124. Each spherical segment 124 has a rubberizedbraking surface 125 that will contact and grip the shaft of a verticalalignment rod. In place of the rubberized braking surface, other typesof non-slip gripping surfaces may be used. A cannulated discoidequatorial spring plate 126 is located between the upper and lowerhemispheres. The equatorial spring plate has a central fenestration 132which permits passage of the alignment rod.

Each brake-bearing spherical segment 124 is pivotally attached to anindividual spring 128. The springs 128 are fixed to and arise from theequatorial spring plate 126 and have a pivot barrel 136 at one endthereof. The pivot barrel 136 of each spring 128 is arranged within apivot trough 134 of the spherical segment 124. There is one spring 128for each spherical segment 124. An axle or rod is placed through eachspherical segment 124 and each pivot barrel 136, pivotally joining eachspherical segment 124 to each spring 128.

The springs 128 hold the spherical segments 124 away from each other,away from the centrally located assembled vertical alignment rod, andaway from the equatorial spring plate 126. In the resting position whenthere is no compression on the brake-bearing 64 it has a sphericalshape. When axial compression is applied to either hemisphere, thesprings 128 will compress. In such situation, the springs 128 will bendin a central direction bringing all the spherical segments 124 of thehemisphere(s) closer together. When the spherical segments 124 arebrought closer together, their braking surfaces 125 will be pressedagainst the centrally positioned vertical alignment rod. The pivot 136attachment of each spherical segment 124 to the spring 128 held toensure contact of each braking surface against the vertical alignmentrod.

A description of the handle 14 will now be provided with reference toFIGS. 34-39C. The handle 14 has a body 200 and a handle-trigger 198which is pivotally attached to the handle body 200 at 202. One end ofthe handle 14 or rostrum 196 is insertable into thelocking-targeting-guide 12. The opposite end of the handle may begrasped by the surgeon or operator to manipulate thelocking-targeting-guide 12.

More specifically, the rostrum 196 is adapted to be inserted into thedocking bay 60 (FIG. 10) of the locking-targeting-guide 12. The topsurface of the rostrum 196 has a rostrum key 194 which providesincreased contact surface area and stability with the docking bay 60. Apressure/lock plate 195 is arranged at the rostrum end 196 of thehandle-trigger 198. When the rostrum 196 is inserted into the dockingbay 60, the pressure lock plate 195 is concealed within the rostrum 196.When the rostrum 196 is completely seated in the docking bay 60, thehandle-trigger 198 may be squeezed or compressed so as to rotate aboutthe pivot 202. Such rotation of handle-trigger 198 will deploy thepressure lock plate 195 concealed within the rostrum 196. The pressurelock plate 195 effectively expands the rostrum 196 within the dockingbay 60 creating a rigid reliable or secure connection between thelocking-targeting-guide 12 and the handle 14.

The shaft of the handle-trigger 198 is divided into three regions, thatis, a first portion or handle-trigger pivot region 219, a second portionor handle-trigger spring region 221, and a third portion orhandle-trigger lock/release/rest region 223. The pivot region 219 isfrom the pressure lock plate 195 to where the handle-trigger shaftcontacts spring post 204. The spring region 221 is the region of thehandle-trigger shaft extending from the contact point with the springpost 204 to flexible latch support 208. The lock/release/reset region223 is the portion of the handle-trigger shaft that supports theflexible latch support 208.

Squeezing or compressing the handle-trigger 198 is initiated after thehandle rostrum 196 has been inserted into the docking bay 60. Thecompression of the handle-trigger 198 is divided into four phases. Thefirst and second phases of handle-trigger 198 compression are utilizedto join the handle 14 to the locking-targeting-guide 12, and the thirdand fourth phases of handle-trigger compression are utilized to activatea locking mechanism within the locking-targeting-guide 12 and releasethe handle 14 from the locking-targeting-guide 12, as hereinbelow morefully described.

The first phase of handle-trigger compression will produce rotation ofthe handle trigger 198 around axle 228 which is positioned in bushing230 of the handle-trigger. Such first phase is completed when thehandle-trigger shaft contacts the spring post 204. The second phase ofcompression forces the handle-trigger 198 to bend against the springpost 204. In this situation, the handle-trigger 198 may bend and behavelike a spring. Such compression of the handle-trigger 198 is continueduntil a palpable/audible click occurs. This click indicates that thehandle-trigger 198 has been locked in the bent spring position. Theaudible/palpable click indicates that the first and second phases ofhandle-trigger compression have been completed.

The audible/palpable click may further indicate that a locking mechanismwithin the handle 14 has been activated to sustain a pressure attachmentof the pressure lock plate 195 within the docking bay 60. Once thehandle 14 has been pressure locked to the locking-targeting-guide 12,the handle 14 and locking-targeting-guide 12 may effectively behave as asingle unit. As a result, the handle 14 can be manipulated to positionthe locking-targeting-guide 12 in a desired position.

The third and fourth phases of handle-trigger compression are initiatedwhen it is desired to lock the locking-targeting-guide 12 in aselected-or desired position. In the third and fourth phases, thehandle-trigger 198 may be maximally or further compressed and thenreleased. The release of the handle-trigger 198 will simultaneouslyrelease the handle 14 from the locking-targeting-guide. The handle 14will also be reset so as to be ready for re-attachment to thelocking-targeting-guide 12 when locating another distal locking screw.

The third phase of handle-trigger 198 compression activates the lockingmechanism in the locking-targeting-guide 12. The third phase ofcompression will deploy a probe 232 from within the handle 14. The probe232 will pass out of the handle rostrum 196 and forcibly press againsttrigger edge 118 of the sliding lock plate 105 (FIG. 16). The slidinglock plate 105 may be displaced against the force of elastic band 122 bythe pressure or force of the probe 232. The displacement of the slidinglock plate 105 will move the horizontal locking bars 116 which willrelease the catches 94 that extend from the bottom of the middle plate66. The release of the catches 94 will permit the compressed lockingsprings 68 to expand which will lift middle plate 66, lower universaljoints 76 a, and brake-bearings 64. This will cause the brake-bearings64 to become compressed between the upper and lower universal joints 42a, 76 a. The compressed brake-bearings 64 will deform and grip theassembled vertical alignment rods locking the locking-targeting-guide 12in the selected position. This sequence will occur very rapidly.

Within body 200 of the handle 14 is spring mounted probe 232 which has along flattened probe bar 242 held in horizontal guide tracks 240. Theguide tracks 240 are located on opposite inner walls 218 of the handlebody 200. The guide tracks permit the probe 232 to have 2 degrees ofhorizontal freedom. The end of the probe 232 at the rostrum of thehandle 196 is substantially flat and normal to the long axis of theprobe. Such rostrum end of the probe is activation end 238. The oppositeend of the probe bar 242 terminates in a cylindrical spring barrel 224.The spring barrel 224 terminates in a discoid spring compression plate222. A coiled probe spring 220 surrounds the spring barrel 224. Theprobe spring 220 is positioned in a cylindrical spring chamber 234 ofthe handle 14. The hemicylindrical walls of the spring chamber 234 maybe molded into the opposite inner walls 218 of the handle body 200.

When the handle rostrum 196 is inserted into the docking bay 60, theprobe activation end 238 is recessed within the rostrum. The probe 232is recessed in the handle by the force of probe spring 220. The probespring 220 pushes against the inner wall of the spring chamber 234 andthe opposite spring compression plate 222 coupled to the probe 232. Thepressure of the spring 220 against the spring compression plate 222keeps the probe 232 positioned within the handle body 200 until thehandle-trigger 198 is compressed.

On the lower surface of the probe bar 242 is a set of brackets 226. Alinking bar 206 is pivotally attached to the brackets 226 by use of anaxle 236. The linking bar 206 is also pivotally attached to a second setof brackets 216 on the upper surface of the handle-trigger 198 by use ofan axle 237. The linking bar 206 extends between the handle-trigger 198and the probe bar 242.

When the handle-trigger 198 is compressed, the linking bar 206 will pushthe probe bar 242 forward toward the handle rostrum 196. During thefirst and second phases of handle-trigger compression, the probe bar 242is advanced through the rostrum so that activation end 238 just contactsthe trigger edge 108 of the sliding lock plate 105. The third and fourthphases of handle-trigger compression will further deploy the activationend 238 of the probe 232 out of the rostrum 196. The additional ormaximum compression of the handle-trigger 198 will produce such furtheror minimum deployment of the activation end 238 of the probe bar 242into the locking-targeting-guide 12. Such deployment of the activationend 238 of the probe 232 will shift the sliding lock plate 105 andactivate the locking mechanism in the locking-targeting-guide 12.

The handle-trigger mechanism which locks after the first and secondphases of handle-trigger compression and releases with the conclusion ofthe third and fourth phases of handle-trigger compression will now befurther described with reference to FIGS. 35 and 36. Arising from therear top surface of the handle-trigger 198 is a vertical flexible latchstem 208 which is substantially normal to the long axis of thehandle-trigger. The latch stem 208 is substantially narrower than thewidth of the handle-trigger 198, and is centered in the handle-trigger198. One end of the latch stem 208 has a horizontal transverse latch210. The width of latch 210 may be substantially equal to the width ofthe handle-trigger 198.

Compression of the handle-trigger 198 forces the latch 210 to makecontact with a lock/release controller 214. There are two identicallock/release controllers 214 arranged or molded into opposites sides ofthe inner walls 218 of the handle body 200. During compression orsqueezing of handle-trigger 198, the transverse latch 210 contacts bothlock/release controllers 214 and the flexible latch stem 208 will passthrough the space between the lock/release controllers 214.

Compression of the handle-trigger 198 will force curved latch slidesurface 209 against angled guide contact surface 212 of controllers 214.The angled guide surfaces 212 of the lock/release controllers 214 willforce the flexible latch stem 208 to bend toward the handle rostrum 196.The slide surface 209 will follow the guide surfaces 212 of thelock/release controllers 214 through the first and second phases ofhandle-trigger compression. The second phase of handle-triggercompression is concluded when the slide surface 209 reaches atermination portion of guide contact surfaces 212. That is, each guidecontact surface 212 terminates in a flat controller lock surface 215which is substantially parallel with the long axis of the handle 14. Theflexible latch stem 208 was progressively bent towards the handlerostrum 196 as the latch slide surface 209 followed the guide contactsurfaces 212 during the first and second phases of handle-triggercompression. When latch lock surface 211 reaches the controller locksurface 215, the bent latch stem 208 will snap back to its originalvertical position and the latch lock surface 211 will be locked againstthe controller lock surface 215. At such time, a palpable/audible snapmay occur as the two surfaces engage.

The latch 210 will remain firmly locked against the controller 214 bythe spring deformation of the handle-trigger 14. That is, the secondphase of handle-trigger compression progressively bent thehandle-trigger 198 against the spring post 204. Therefore, the secondphase of handle-trigger compression produces spring deformation in thehandle-trigger which produces a reliable pressure lock of the latch locksurface 211 against the controller lock surfaces 215.

When the third and fourth phases of handle-trigger compression areinitiated, the latch slide surface 209 will be forced against secondangled guide surfaces 213 of the lock/release controllers 214 which willforce the flexible latch stem 208 to bend towards the handle rostrum196. The third and fourth phases of handle-trigger compression areconcluded when the latch slide surface 209 reaches the apex of thesecond guide surfaces 213.

At the termination of the second guide surfaces 213, the bent latch stem208 may snap back to its original vertical position. At such time, anaudible/palpable snap may occur which may be detected by the surgeon. Assuch, the surgeon will also recognize that the handle-trigger 198 maynot be further compressed.

When compression of the handle-trigger 198 has been completed butcompression has not yet been released, the latch stem 208 will havereturned to its original vertical position. The latch 210 will belocated behind the lock/release controllers 214. When compression of thehandle-trigger 198 is released, the latch 210 will ride againstcontroller release/reset surfaces 217 which will force the latch stem208 to bend towards the rear of the handle 14, away from the rostrum196. The latch 210 will follow the controller release/reset surfaces 217as the handle-trigger 198 is released.

When the latch 210 reaches the lower termination of the controllerrelease/reset surfaces 217, the latch stem 208 will snap back to itsoriginal vertical position. As such, the latch 210 will be reset to itsoriginal position beneath the lock/release controllers 214. Thehandle-trigger 198 is returned to its original position by the combinedrelease of the spring deformation of the handle-trigger 198 and theforce of the expanding probe spring 220.

The return of the handle-trigger 198 to its original noncompressedposition terminates the pressure grip of the handle-trigger pressurelock plate 195 within the docking bay 60 of the locking-targeting-guide12. As a result, the handle 14 may be easily detached from thelocking-targeting-guide 12.

A description of an operation involving the present apparatus, will nowbe provided.

The present apparatus may be used after the intramedullary nail has beenplaced into the bone. More specifically, initially the foundation 10 ofthe present apparatus is attached to the injured limb, over the distalscrew holes of the implanted intramedullary nail. Brief intraoperativex-rays may be used to position the foundation 10 on the skin over thedistal screw holes of the implanted intramedullary nail. The foundation10 may then be attached to the underlying bone with a plurality of metalfixation pins 25 placed between the foundation and the patient and whichmay be drilled into the underlying bone. Alternatively, the foundation10 may be fixed to the limb with a relatively wide neoprene strap 250.

After the foundation 10 is rigidly attached to the limb, thelocking-targeting-guide 12 is snapped onto the foundation 10. Theremovable handle 14 is then snapped into the locking-targeting-guide 12.Next, the factory or pre-assembled restraining plate 16 (which preventedpremature motion of the locking-targeting-guide) may be removed from thetop of the locking-targeting-guide 12 and replaced by the removabletargeting insert 24. After the targeting insert 24 is snapped into thelocking-targeting-guide 12, the freedom lever 158 may be released on thefoundation 10. Such foundation freedom lever also prevented prematuremotion of the locking-targeting-guide 12.

The release of the foundation freedom lever 158 permits thelocking-targeting-guide 12 to have substantially unrestricted motionthrough a number (such as six) of degrees of freedom as directed by thehandle 14. Brief intraoperative x-rays may be used to guide thepositioning of the locking-targeting-guide 12 over a distal screw hole.As a result, the targeting insert 24 may be easily positioned directlyover a distal screw hole in the implanted intramedullary nail.

The intraoperative portable x-ray is positioned such that the path ofthe x-ray beam is parallel with a selected distal screw hole. As such,the screw hole will appear as a substantially perfect clear circle onthe x-ray monitor. When the targeting insert 24 is positioned over thescrew hole it will appear as a circular black spot centered in the screwhole.

When the targeting insert 24 is properly positioned over the screw hole,the handle 14 is rapidly but gently squeezed. The handle 14 willactivate the locking mechanism in the locking-targeting-guide 12 so asto fix the locking-targeting-guide directly over the screw hole.

The handle 14 may perform three functions. That is, the handle may beused to position the locking-targeting-guide 12, to trigger the lockingmechanism within the locking-targeting-guide 12, and to spontaneouslydetach from the locking-targeting-guide after the locking mechanism ofthe locking-targeting-guide has been triggered. Since, the weight of thehandle 14 extending from the locking-targeting-guide 12 may represent apotential deforming force, it is advantageous to remove the handle afterthe locking-targeting-device has been locked in a selected position.

After the handle 14 has been detached from the positionedlocking-targeting-guide 12, the targeting insert 24 may be removed andreplaced with the cannulated drill insert 34. The cannulated drillinsert 34 may be used to guide a drill to bore a hole properly acrossthe bone and through the screw hole of the intramedullary nail. The samecannulated drill insert 34 can be used to guide a depth gauge across thebone so as to measure the optimum length of the distal locking screw.Additionally, the same cannulated drill insert 34 may be used to guide ascrew driver with the selected locking screw. X-rays are not requiredfor such steps which use the drill insert.

After the first distal screw has been implanted, the portable x-raymachine is repositioned to place the x-ray beam parallel with the longaxis of the second distal screw hole. (Interlocking intramedullary nailsmay use at least two distal locking screws.) The present apparatus isthen reset so as to be positioned over the second distal screw hole.When locating the second distal screw hole, the foundation 10 does notneed to be adjusted. The locking mechanism in thelocking-alignment-guide 12 is released and reset. Such releasing andresetting of the locking mechanism in the locking-targeting-guide 12 isachieved by manually compressing two plates 54 that extend from oppositesides of the locking-targeting-guide. The handle 14 is once againsnapped onto the locking-targeting-guide 12, and the targeting insert 24is set in place. The present apparatus is then ready to locate thesecond distal screw hole and facilitate the implantation of the seconddistal locking screw in a manner similar to that involving the firstdistal screw. Accordingly, the present device enables a rapid and easyreset to guide the drilling of the second screw hole, to guide themeasurement of the second locking screw, and to guide the insertion ofthe second locking screw.

Other embodiments of the present invention will now be discussed withreference to FIGS. 40-48.

Apparatus 500 includes a locking-targeting-guide 512 and a positioninghandle 514. The locking-targeting-guide 512 may function with thepreviously described foundation 10 or with foundations 516 or 518,hereinafter described, in a substantially similar manner to that oflocking-targeting-guide 12 and locking-targeting-guide 512 may includemechanical elements that are substantially similar to those oflocking-targeting-guide 12.

With reference to FIGS. 43-46, features/elements oflocking-targeting-guide 512 will now be described. Thelocking-targeting-guide 512 has a top frame 546 and a bottom frame 575which may be compressed together. Such compression of bottom frame 575and top frame 546 will activate mechanisms that will releasably lock theframes 546 and 575 together and releasably compress brake-bearings 564onto vertical alignment rods 146 (FIG. 28). The brake-bearings 564 aresubstantially similar to and function in a substantially similar mannerto the brake-bearings 64 (FIGS. 20, 21, 22).

The top frame 546 and bottom frame 575 are forcibly separated by aplurality of springs 568. Compression of the bottom frame 575 and thetop frame 546 is resisted by the springs 568. Complete dissociation ofthe top frame 546 from the bottom frame 575 produced by the pressure ofthe springs 568 against the under side of surface 520 is prevented byassembly screws 544, or other types of fasteners, that are screwed (orarranged) into spring support pillars 570. The diameter of the head ofthe assembly screw 544 (or fastener) may be larger than the diameter ofthe spring support pillar 570. The assembly screw head may rest on thesurface 520 or may be recessed into the surface 520. When the top plate546 and the bottom plate 575 are compressed together, the spring supportpillars 570 may be permitted to rise through the fenestrations 562.

The top frame 546 has a plurality of lock-release levers 554 that arepivotally attached to top frame 546 in recesses 504. Each lock-releaselever 554 may have an axle 560 and a spring 566 or similar mechanism toforcibly maintain a vertical orientation of the lock-release lever 554.Pressure against upper outer surface 506 of lock-release lever 554 willpivot the lock-release lever about the axle 560.

With reference to FIGS. 43, 45 and 46, the bottom frame 575 has alocking rim 572 that is in contact with the inner surface of the topframe 546 when the locking-targeting-guide 512 is properly assembled.When compression is applied to the locking-targeting-guide 512, thelocking rim 572 will contact the lever slide 582. Compression of thebottom frame 575 and the top frame 546 will cause the lock-release lever554 to pivot about the axle 560 against the force of the spring 566.Such compression is continued until undersurface 586 of the locking rim572 engages lock lever catch 580 of the lock-release lever 554.

When the undersurface 586 of the locking rim 572 meets the lock levercatch-580, the spring 566 will forcibly pivot the lock-release lever 554to a vertical position. Such movement of the lock-release lever 554 to avertical position will releasably engage the lock lever catch 580against the undersurface 586 of the locking rim 572 so as to lock thebottom frame 575 and the top frame 546 together.

The bottom frame 575 may be released from the top frame 546 by applyingpressure against upper outer surfaces 506 of the lock-release levers 554which causes catch surfaces 580 to pivot away from the locking rims 572.When the catch surfaces 580 are pivoted away from the locking rims 572,the springs 568 will expand and displace the top frame 546 from thebottom frame 575.

Within the bottom frame 575 there is an armature 574 that has aplurality of universal joints 576 a. Above each universal joint 576 a isa respective brake-bearing 564. Armature 574 and universal joints 576 aare substantially similar to armature 74 and lower universal joints 76 a(FIGS. 11 and 13). The armature 574 is positioned above a uniformcompression distributor 528.

The uniform compression distributor 528 may be formed from a sheet offirm compressible closed cell foam 534 or similar compressibleexpandable material that will deform when pressure is applied to it butexert pressure against the deforming force. Release of the deformingforce will permit the closed cell foam 534 to expand to its originalshape. Interposed between the sheet of closed cell foam 534 and beneaththe armature 574 is a smooth rigid slide sheet 532. The armature 574 mayslide through a number of degrees of freedom on the slide sheet 532. Theundersurface of the armature 574 and the slide sheet 532 are composed ofmaterials having a relatively low coefficient of friction, such asTeflon or the like.

With reference to FIG. 42, the upper surface 520 of the top frame 546has a plurality of universal joints 542 a that are substantially similarto and function in a substantially similar manner to the universaljoints 42 a of locking-targeting-guide 12 (FIG. 10). In the center ofthe upper surface 520 is a relatively large central fenestration 545.The central fenestration 545 is substantially similar to the largecentral fenestration 45 of locking-targeting-guide 12. The centralfenestration 545 will accept the previously described alignment rodrestraining plate 16 (FIG. 2), the targeting insert 24, and thecannulated insert 34 (FIGS. 7, 8, 9).

Activation of the locking mechanism of the brake-bearings 564 againstthe vertical alignment rods 146 is produced by compression of theuniversal joints 542 a and 576 a against the upper and lower hemispheresof the brake-bearing 564 (FIG. 43). This compression is partiallyachieved by compressing the top frame 546 and bottom frame 575 together.Contact of the upper universal joints 542 a and lower universal joints576 a against the upper and lower hemispheres of the brake-bearings 564occurs before the bottom frame 575 has been locked to the top frame 546.The additional compression required to lock the bottom frame 575 to thetop frame 546 may compress the armature 574 against the uniformcompression distributor 528.

The pressure of the armature 574 against the universal compressiondistributor 528 is resisted by the closed cell foam 534. The compressedclosed cell foam 534 will exert an expansion pressure against thearmature 574. The pressure of the universal compression distributor 528against the armature 574 ensures adequate sustained compression of theuniversal joints 542 a and 576 a against the brake-bearings 564 so as toprovide sustained locking of the brake-bearings 564 against the verticalalignment rods 146.

With reference to FIGS. 40, 41, 44 a, and 44 b, positioning handle 514will be described. The handle 514 may function in a substantiallysimilar fashion as handle 14 (FIG. 1). That is, handle 514 willreleasably rigidly couple to the locking-targeting-guide 512, willactivate the lock mechanism within the locking-targeting-guide 512against the vertical alignment rods, and upon locking thelocking-targeting-guide 512 in the desired position the handle 514 canbe uncoupled from locking-targeting-guide 512.

A number of elements of the handle 514 are different from handle 14.Handle 514 may have five major components that include an uppercompression fork 594, a lower compression fork 598, a handle body 604, ahandle trigger 602, and a spring 502. The handle trigger 602 and thehandle body 604 may be pivotally linked together through axle 608. Thehandle trigger 602 and the handle body 604 may be pivotally linked toboth the upper compression fork 594 and the lower compression fork 598.

The front end of the handle body 604 terminates in a linking fork 612.The linking fork 612 has a fixed pivot 606 with the rear end of theupper compression fork. The linking fork has a sliding pivot 618 with aslide groove 622 in the lower compression fork 598. The front end of thetrigger 602 terminates in a linking fork 614. The linking fork 614 has afixed pivot 610 with the rear end of the lower compression fork. Thelinking fork 614 has a sliding pivot 616 with a slide groove 620 in theupper compression fork 594.

Arising from the rear top surface of the handle-trigger 602 is avertical flexible latch stem 508 which is substantially normal to thelong axis of the handle-trigger. The vertical flexible latch stem 508terminates in a latch 538. The flexible latch stem 508 and latch 538 aresubstantially similar to and function in a substantially similar mannerto flexible latch stem 208 and latch 214 of handle trigger 198 (FIG.36). Two lock/release controllers are arranged or molded into oppositessides of the inner walls of the handle body 604 that are substantiallysimilar to and function in a substantially similar manner to thelock-release controller 214 (FIG. 36).

The spring 502 distracts the handle body 604 from the handle trigger602. When the handle body is maximally distracted from the trigger 602,the interval between upper compression fork 594 and lower compressionfork 598 is at a maximum. Such maximum interval between the uppercompression fork 594 and the lower compression fork 598 is greater thanthe maximal height of the locking-targeting-guide 512 when springs 568(FIG. 43) are maximally expanded.

Compressing the handle trigger 602 towards handle body 604 will narrowthe interval between the upper compression fork 594 and the lowercompression fork 598. The upper compression fork 594 and lowercompression fork 598 are arranged so as to be substantially parallel toone another even as the interval between forks 594 and 598 is narrowed.

The upper compression fork terminates in a pair of tines 596. The tines596 are adapted to engage the top surface 520 of thelocking-targeting-guide 512. The locking-targeting-guide 512 has anelevated ridge 522 (FIG. 42) that guides and positions the tines 596.The lower compression fork 598 terminates in a pair of tines 600. Topsurfaces 626 of tines 600 may engage lower surfaces of buttresses 556(FIG. 42) of the bottom frame 575 of the locking-targeting-guide 512.

The locking-targeting-guide 512 is adapted to be grasped-and compressedby the handle 514. The sequence of the engagement and operation of thehandle 514 with the locking-targeting-guide 512 is described below.

The fully expanded locking-targeting-guide 512 is placed into theinterval between the upper and lower compression forks 594 and 598. Thetrigger 602 is squeezed against the force of the spring 502 and theinterval between the compression forks 594 and 598 is narrowed such thatthe compression forks 594 and 598 engage the top and bottom of thelocking-targeting-guide 512. Compression on the trigger 502 iscontinued. The continued compression will continue to narrow theinterval between the compression forks 594 and 598 and initiatecompression between the bottom frame 575 and the top frame 546 of thelocking-targeting-guide 512 against the force of springs 568.Compression of the trigger is continued until the latch 538 engages andlocks with the lock-release controller in the handle body 604. When thetrigger 602 is locked to the handle body 604, the lock is sustained bythe compressed spring 502. When the locking-targeting-guide 512 iscompressed between the upper and lower compression forks 594 and 598,the expansible force of the compressed spring(s) 568 rigidly couples thelocking-targeting-guide 512 to the handle 514. The handle 514 can now beused to move the locking-targeting-guide 512 to a desired position.

When the desired position of the locking-targeting-guide 512 isselected, the trigger 602 is squeezed another time. Such additionalcompression of the trigger 602 will produce further compression betweenthe bottom frame 575 and the top frame 546 and produce compression ofthe brake-bearings 564 against the vertical alignment rods and lockingof the bottom frame 575 to the top frame 546. Compression of the trigger602 may be terminated when an operator hears a first click caused by theactivation of the lock mechanism in locking-targeting-guide 512 and asecond click as the latch 538 passes over the lock-release controller.Release of the trigger 602 will permit the spring 502 to expand andmaximally widen the interval between the upper and lower compressionforks'so as to enable the handle 514 to be uncoupled from-thelocking-targeting-guide 512.

Reactivation of the locking-targeting-guide 512 is achieved bycompressing the upper outer surface 506 of the lock-release levers 554(FIG. 42). This will release the bottom frame 575 from top frame 546 andpermit the locking-targeting-guide 512 to re-expand and release thebrake-bearings 564 from the vertical alignment rods 146. Thereafter,handle 514 can be coupled to the locking-targeting-guide 512 and theprocess of moving and locking of the locking-targeting-guide in anotherdesired position repeated.

Alternative embodiments of foundation 10 (FIGS. 1 and 28) will now bedescribed with reference to FIGS. 47 and 48.

Foundation 518 is similar to the foundation 10, except that thefoundation 518 may be mounted directly to a hospital bed, an operativetable or a radiographic table. Hospital beds, operative tables, andradiographic imaging tables have side rails to which portable medicalequipment can be releasably attached. The foundation 518 has an openingor tenon 524 with two sides 530 adapted to be arranged on the side railand may be held in place by tightening knob 526. Foundation 510 issimilar to the foundation 10, except that foundation 510 is pivotallyattached to an independent free standing portable armature 516, as shownin FIG. 48.

Accordingly, the present invention provides a technique for targetingand/or installing distal locking screws into intramedullary nails whichis relatively simple and intuitive to use. The present technique may beused with equipment presently available, in most, if not all, hospitalsand as such does not require additional and possibly expensive pieces ofequipment. The present technique substantially minimizes x-ray exposurethrough the above-described four steps of distal screw placement and yetwill enable a rapid and reliable guide for the drilling of the distalscrew holes, the measuring of the locking screw(s) and the placement ofthe locking screw(s). Further, the present technique may significantlydecrease operating room time. Furthermore, the present apparatus may bealmost completely radiolucent. Additionally, since a number of theparts/elements of the present apparatus may be fabricated or molded fromplastic, the present invention is relatively inexpensive and may bedisposable.

Although the present apparatus has been described with certain typesand/or numbers of elements, the present apparatus is not so limited andmay instead have other types and/or numbers of elements. For example,although the present apparatus was described as having four verticalalignment rods 146 and four break-bearing devices 64, the presentapparatus may instead have three (or another number) of such rods and/orbreak-bearing devices. As another example, although the presentapparatus was described as having an equal number of assembled verticalalignment rods, brake-bearings 64, and universal joints, the presentapparatus is not so limited and may have an unequal number of suchelements.

Further, although the present apparatus has been described for use withdistal locking screws, the present apparatus is not so limited and mayinstead be used with proximal locking and other types of fasteners.

Furthermore, although embodiments of the present invention have beendescribed for use in the placement of orthopaedic screws into animplanted intramedullary nail, the present invention is not so limitedand is not limited to orthopaedic applications. That is, the presentinvention can be applied in any medical situation or procedure where aposition is to be determined and maintained. For example, the presentinvention may be used for x-ray guided biopsies, x-ray guided placementof a catheter for drainage of an abscess or similar abnormal collectionof fluid and so forth.

Although preferred embodiments of the present invention andmodifications thereof have been described in detail herein, it is to beunderstood that this invention is not limited to these embodiments andmodifications, and that other modifications and variations may beeffected by one skilled in the art without departing from the spirit andscope of the invention as defined by the appended claims.

What is claimed is:
 1. An apparatus for installing a number of distalscrews into an intramedullary nail implanted in a patient, saidapparatus comprising: a foundation unit adapted to be fixedly coupled tosaid patient; a targeting/guiding unit adapted to be attached to saidfoundation unit and adaptable for targeting and guiding a device ordevices used in installing a respective distal screw into a distal holein said intramedullary nail, said targeting/guiding unit being movableto a desired location by an operator when attached to said foundationdevice so as to be aligned with the respective distal screw hole,wherein said targeting/guiding unit includes a locking device forholding said targeting/guiding unit in said desired location; a handleadapted to be coupled to said targeting/guiding unit for facilitatingthe movement thereof by said operator, wherein said handle includesmeans for activating said locking device.
 2. A apparatus according toclaim 1, wherein said targeting/guiding unit further includes means forreleasing said locking device such that said targeting/guiding unit isnot held in said desired location.
 3. An apparatus according to claim 1,wherein said foundation unit includes a number of alignment rods andwherein said targeting/guiding unit is attachable to said number ofalignment rods.
 4. An apparatus according to claim 3, wherein saidnumber of alignment rods are movably arranged in said foundation device.5. An apparatus according to claim 4, wherein said locking deviceincludes a number of brake elements each coupled to a respectivealignment rod.
 6. An apparatus according to claim 1, wherein said handlefurther includes means for de-coupling said handle from saidtargeting/guiding unit when the activating means activates said lockingdevice.